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BACKGROUND: Aortic root evaluation is conventionally based on two-dimensional measurements at a single phase of the cardiac cycle. This work presents an image analysis method for assessing dynamic three-dimensional changes in the aortic root of minimally calcified bicuspid aortic valves (BAVs) with and without moderate to severe aortic regurgitation. METHODS: The aortic root was segmented over the full cardiac cycle in three-dimensional transesophageal echocardiographic images acquired from 19 patients with minimally calcified BAVs and from 16 patients with physiologically normal tricuspid aortic valves (TAVs). The size and dynamics of the aortic root were assessed using the following image-derived measurements: absolute mean root volume and mean area at the level of the ventriculoaortic junction, sinuses of Valsalva, and sinotubular junction, as well as normalized root volume change and normalized area change of the ventriculoaortic junction, sinuses of Valsalva, and sinotubular junction over the cardiac cycle. RESULTS: Normalized volume change over the cardiac cycle was significantly greater in BAV roots with moderate to severe regurgitation than in normal TAV roots and in BAV roots with no or mild regurgitation. Aortic root dynamics were most significantly different at the mid-level of the sinuses of Valsalva in BAVs with moderate to severe regurgitation than in competent TAVs and BAVs. CONCLUSIONS: Echocardiographic reconstruction of the aortic root demonstrates significant differences in dynamics of BAV roots with moderate to severe regurgitation relative to physiologically normal TAVs and competent BAVs. This finding may have implications for risk of future dilatation, dissection, or rupture, which warrant further investigation.

Thoracic skeletal injury is a common outcome of motor vehicle accidents. Skeletal reconstruction is guided by anatomic and physiologic variables dictated by the injury complex. Here we describe a report of a patient who sustained complex trauma to the thorax leading to complete thoracic dissociation. Clinical and operative decision-making is discussed to inform the reader of a proposed ordered protocol and considerations for operative intervention and reconstruction.

Background The saddle shape of the normal mitral annulus has been quantitatively described by several groups. There is strong evidence that this shape is important to valve function. A more complete understanding of regional annular geometry in diseased valves may provide a more educated approach to annuloplasty ring selection and design. We hypothesized that mitral annular shape is markedly distorted in patients with diseased valves. Methods Real-time 3-dimensional echocardiography was performed in 20 patients with normal mitral valves, 10 with ischemic mitral regurgitation, and 20 with myxomatous mitral regurgitation (MMR). Thirty-six annular points were defined to generate a 3-dimensional model of the annulus. Regional annular parameters were measured from these renderings. Left ventricular inner diameter was obtained from 2-dimensional echocardiographic images. Results Annular geometry was significantly different among the three groups. The annuli were larger in the MMR and in the ischemic mitral regurgitation groups. The annular enlargement was greater and more pervasive in the MMR group. Both diseases were associated with annular flattening, although though the regional distribution of that flattening was different between groups. Left ventricular inner diameter was increased in both groups. However, relative to the Left ventricular inner diameter, the annulus was disproportionately dilated in the MMR group. Conclusions Patients with MMR and ischemic mitral regurgitation have enlarged and flattened annuli. In the case of MMR, annular distortions may be the driving factor leading to valve incompetence. These data suggest that the goal of annuloplasty should be the restoration of normal annular saddle shape and that the use of flexible, partial, and flat rings may be ill advised.

Background The effect of aortic valve replacement on three-dimensional mitral annular geometry has not been well described. Emerging transcatheter approaches for aortic valve replacement employ fundamentally different mechanical techniques for achieving fixation and seal of the prosthetic valve than standard surgical aortic valve replacement. This study compares the immediate impact of transcatheter aortic valve replacement (TAVR) and standard surgical aortic valve replacement (AVR) on mitral annular anatomy. Methods Real-time three-dimensional echocardiography was performed in patients undergoing TAVR using the Edwards Sapien valve (n = 10 [Edwards Lifesciences, Irvine, CA]) or AVR (n = 10) for severe aortic stenosis. Mitral annular geometric indexes were measured using Tomtec EchoView (Tomtec Imaging Systems, Munich, Germany) to assess regional and global annular geometry. Results Mixed between-within analysis of variance showed no differences between TAVR and AVR groups in any of the mitral annular geometric indices preoperatively. However, postoperative analysis did demonstrate an effect of AVR on geometry. Patients undergoing open AVR had significant decrease in annular height, septolateral diameter, mitral valve transverse diameter, and mitral annular area after valve replacement (p ≤ 0.006). Similar changes were not noted in the TAVR group. Conclusions Mitral annular geometry is better preserved by TAVR than by AVR. Thus, TAVR may be a more physiologic approach to aortic replacement.

Background A comprehensive three-dimensional echocardiography based approach is applied to preoperative mitral valve (MV) analysis in patients with ischemic mitral regurgitation (IMR). This method is used to characterize the heterogeneous nature of the pathologic anatomy associated with IMR. Methods Intraoperative real-time three-dimensional transesophageal echocardiograms of 18 patients with IMR (10 with anterior, 8 with inferior infarcts) and 17 patients with normal MV were analyzed. A customized image analysis protocol was used to assess global and regional determinants of annular size and shape, leaflet tethering and curvature, relative papillary muscle anatomy, and anatomic regurgitant orifice area. Results Both mitral annular area and MV tenting volume were increased in the IMR group as compared with patients with normal MV (mitral annular area=1,065 ± 59 mm 2 versus 779 ± 44 mm 2 , p = 0.001; and MV tenting volume=3,413 ± 403 mm 3 versus 1,696 ± 200 mm 3 , p = 0.001, respectively). Within the IMR group, patients with anterior infarct had larger annuli (1,168 ± 99 mm 2 ) and greater tenting volumes (4,260 ± 779 mm 3 versus 2,735 ± 245 mm 3 , p = 0.06) than the inferior infarct subgroup. Papillary-annular distance was increased in the IMR group relative to normal; these distances were largest in patients with anterior infarcts. Whereas patients with normal MV had very consistent anatomic determinants, annular shape and leaflet tenting distribution in the IMR group were exceedingly variable. Mean anatomic regurgitant orifice area was 25.8 ± 3.0 mm 2 , and the number of discrete regurgitant orifices varied from 1 to 4. Conclusions Application of custom analysis techniques to three-dimensional echocardiography images allows a quantitative and systematic analysis of the MV, and demonstrates the extreme variability in pathologic anatomy that occurs in patients with severe IMR.

Backgound Stroke has emerged as an important complication of thoracic endovascular aortic repair (TEVAR). Identifying risk factors for stroke is important to define the risks of this procedure. Methods All neurologic complications were analyzed in a prospective database of patients in thoracic aortic stent graft trials from 1999 to 2006. Serial neurological examination was performed. Stroke was defined as any new onset focal neurologic deficit. Results The TEVAR was performed on 171 patients; 52 had lesions requiring coverage of the proximal descending thoracic aorta (extent A), 50 requiring coverage of the distal descending aorta (extent B), and 69 requiring coverage of the entire descending thoracic aorta (extent C). The incidence of stroke was 5.8%. Eighty-nine percent (8 of 9) of strokes occurred within 24 hours of operation. Stroke was associated with a 33% in-hospital mortality rate. Risk factors identified for stroke included prior stroke (odds ratio [OR] 9.4, confidence interval [CI] 2.3 to 38.1, p = 0.002) and extent A or C coverage (OR 5.5, CI 1.7–12.5, p = 0.001). The stroke rate in patients with both prior stroke and extent A or C coverage was 27.7%. Severe atheromatous disease involving the aortic arch by computed tomographic scan was strongly associated with perioperative stroke (OR = 14.8, CI 1.7 to 675.6, p = 0.0016). Transesophageal echocardiography demonstrated mobile atheroma in two patients with stroke. Conclusions Stroke after TEVAR was associated with a high mortality. The TEVAR of the proximal descending aorta (extent A or C) in patients with a history of stroke had the highest perioperative stroke rate. These risk factors, together with high grade aortic atheroma of the aortic arch, predicted a high probability for cerebral embolization and can be used to identify patients at high risk for stroke as a consequence of TEVAR.

Stroke occurs in 2% to 5% and cognitive dysfunction occurs acutely in 60% to 80% of patients early after cardiac surgery. Both may have long-term consequences. Research into mechanisms behind these sequelae has been focused intraoperatively, although there is little reason to believe that injury is limited to this period. Aging prominently increases the incidence of these sequelae. Anemia with cardiac surgery is acute and severe, should cause an increase in cerebral blood flow (CBF), and may impact stroke and cognitive function in this setting. To better understand changes in perioperative CBF physiology we have measured changes in CBF and the influence of anemia and aging on these changes.Cerebral blood flow was measured using the noninvasive continuous arterial spin labeling perfusion magnetic resonance imaging method. Cerebral blood flow, mean arterial pressure, hemoglobin, hemoglobin oxygen saturation, and cardiopulmonary bypass time were recorded in 12 subjects before and 6 +/- 2 days after cardiac surgery.Cerebral blood flow increased from 44.6 +/- 15.6 mL100 g(-1)min(-1) to 64.4 +/- 20.1 mL100 g(-1)min(-1) after cardiac surgery, or 49.1% +/- 26.7%, (p0.0001). The absolute change in CBF (DeltaCBF) was predicted by the following regression model: DeltaCBF = -55 + 0.64(Age) + 0.53(CBF(Pre)) -3.3(DeltaHgb); R(2) = 0.81; p = 0.003, where CBF(Pre) is the baseline preoperative CBF and DeltaHgb is the change in hemoglobin from preoperative to postoperative periods.Cerebral blood flow increases after cardiac surgery, and anemia appears to be an important cause. Age appears also to be an important covariate, with advancing age further increasing the magnitude of this hyperemia. The interrelationship of aging and anemia, in determining perioperative changes in CBF, and potentially cerebral oxygenation, may have important implications for the understanding of perioperative stroke and cognitive dysfunction after cardiac surgery.

The duration, severity, and cause of hypotension after intravenous amiodarone has not been well characterized in anesthetized cardiac surgical patients. Because amiodarone is tolerated in patients with advanced cardiac disease, we hypothesized that left ventricular systolic performance is preserved despite hypotension during amiodarone loading.In a prospective double-blind trial, 30 patients undergoing coronary artery bypass graft (CABG) surgery were randomly assigned to receive intravenous amiodarone (n = 15) or placebo (n = 15). Cardiac output (CO), mixed venous oxygen saturation (SVO), arterial blood pressure (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP]), pulmonary artery pressure, and central venous pressure (CVP) were recorded. Transesophageal echocardiographic left ventricular end-diastolic area (EDA), end-systolic area (ESA), fractional area change (FAC), and end-systolic wall stress (ESWS) were measured every 5 minutes.Mean arterial pressure, SBP, and DBP decreased over time after drug administration in both groups (p0.05). At 6 minutes, amiodarone decreased the MAP by 14 mm Hg (p = 0.004) and placebo decreased the MAP by 4 mm Hg. The change in MAP, SBP, and DBP between groups was statistically different for the first 15 minutes after drug administration. Hypotension requiring intervention occurred in 3 of 15 after amiodarone and 0 of 15 after placebo (p = 0.22). The mean heart rate was 11.5 beats per minute less after amiodarone (p0.02), but pulmonary artery pressure, CVP, SVO, and FAC were not different between groups.Intravenous amiodarone decreased heart rate and caused a significant, but transient decrease in arterial pressure in the first 15 minutes after administration. Left ventricular performance was maintained suggesting that selective arterial vasodilation was the primary cause of drug-induced hypotension.

Background . Electrophysiologic studies during rewarming after deep hypothermic circulatory arrest probe the state of the brain during this critical period and may provide insight into the neurological effects of circulatory arrest and the neurologic outcome. Methods . Electroencephalogram (EEG) and evoked potentials were monitored during rewarming in 109 patients undergoing aortic surgery with hypothermic circulatory arrest. Results . The sequence of neurophysiologic events during rewarming did not mirror the events during cooling. The evoked potentials recovered first followed by EEG burst-suppression and then continuous EEG. The time to recovery of the evoked potentials N20-P22 complex was significantly correlated with the time of circulatory arrest even in patients without postoperative neurologic deficits (r = 0.37, ( p = 0.002). The nasopharyngeal temperatures at which continuous EEG activity and the N20-P22 complex returned were strongly correlated (r = 0.44, p = 0.0002; r=0.41, p = 0.00003) with postoperative neurologic impairment. Specifically, the relative risk for postoperative neurologic impairment increased by a factor of 1.56 (95% CI 1.1 to 2.2) for every degree increase in temperature at which the EEG first became continuous. Conclusions . No trend toward shortened recovery times or improved neurologic outcome was noted with lower temperatures at circulatory arrest, indicating that the process of cooling to electrocerebral silence produced a relatively uniform degree of cerebral protection, independent of the actual nasopharyngeal temperature.

Background Surgical techniques for aortic valve (AV) repair are directed toward restoring normal structural relationships in the aortic root and rely on detailed assessment of root and valve anatomy. Noninvasive three-dimensional (3D) imaging and modeling may assist in patient selection and operative planning. Methods Transesophageal real-time 3D echocardiographic images of 5 patients with normal AVs were acquired. The aortic root and the annulus were manually segmented at end diastole using a 36-point rotational template. The AV leaflets and the coaptation zone were manually segmented in parallel 1-mm cross sections. Quantitative 3D models of the AV and root were generated and used to measure standard anatomic parameters and were compared to conventional two-dimensional echocardiographic measurements. All measurements are given as mean ± SD. Results Annular, sinus, and sinotubular junction areas were 4.1 ± 0.6 cm 2 , 7.5 ± 1.2 cm 2 , and 3.9 ± 1.0 cm 2 , respectively. Root diameters (measured in three locations) by 3D model inspection and two-dimensional echocardiography measurement correlated (R 2 = 0.75). Noncoapted areas of the left, right, and noncoronary leaflets were 1.9 ± 0.2 cm 2 , 1.6 ± 0.3 cm 2 , and 1.6 ± 0.3 cm 2 , respectively. Mean coaptation areas for the left-right, left-noncoronary, and right-noncoronary coaptation zones were 87.7 ± 36.9 mm 2 , 69.9 ± 20.7 mm 2 , and 114.2 ± 23.0 mm 2 , respectively. The mean ratio of noncoapted leaflet area to annular area was 1.3 ± 0.2. Conclusions High-resolution 3D models of the in vivo normal human aortic root and valve were generated using 3D echocardiography. Quantitative 3D models and analysis may assist in characterization of pathology and decision making for AV repair.

Background The primary goal of surgical mitral repair is the reestablishment of normal leaflet coaptation. Surgical techniques that maintain or restore leaflet geometry promote leaflet coaptation. Recent 3-dimensional (3D) echocardiographic studies have shown that saddle-shaped annuloplasty has a salutary influence on leaflet geometry. Therefore we hypothesized that saddle-shaped annuloplasty would improve leaflet coaptation in cases of repair for flail posterior leaflet segments. Methods Sixteen patients with flail posterior segment and severe mitral regurgitation had valve repair using standard techniques. Eight patients received saddle-shaped annuloplasty and 8 patients received flat annuloplasty. Real-time 3D transesophageal echocardiography was performed before and after repair. Images were analyzed using custom software to calculate mitral annular area (MAA), septolateral dimension (SLD), intercommissural width (CW), total leaflet area (TLA), and leaflet coaptation area (LCA). Results Postrepair MAA (flat, 588.6 ± 26.5 mm 2 ; saddle, 628.0 ± 35.3 mm 2 ; p = 0.12) and TLA (flat, 2198.5 ± 151.6 mm 2 ; saddle, 2303.9 ± 183.8 mm 2 ; p = 0.67) were similar in both groups. Postrepair LCA was significantly greater in the saddle group than in the flat group (226.8 ± 24.0 mm 2 and 154.0 ± 13.0 mm 2 , respectively; p = 0.02). Conclusions Real-time 3D echocardiography and novel imaging software provide a powerful tool for analyzing mitral leaflet coaptation. When compared with flat annuloplasty, saddle-shaped annuloplasty improves LCA after mitral valve repair for severe mitral regurgitation secondary to flail posterior leaflet segment. Use of saddle-shaped annuloplasty devices may increase repair durability.

Background Paraplegia is a recognized complication after endovascular stent repair of descending thoracic aortic aneurysms. A management algorithm employing neurologic assessment, somatosensory evoked potential monitoring, arterial pressure augmentation, and cerebrospinal fluid drainage evolved to decrease the risk of postoperative paraplegia. Methods Patients in thoracic aortic aneurysm stent trials from 1999 to 2004 were analyzed for paraplegic complications. Lower extremity strength was assessed after anesthesia and in the intensive care unit. A loss of lower extremity somatosensory evoked potential or lower extremity strength was treated emergently to maintain a mean arterial pressure 90 mmHg or greater and a cerebrospinal fluid pressure 10 mm Hg or less. Results Seventy-five patients (male = 49, female=26, age=75 ± 7.4 years) had descending thoracic aortic aneurysms repaired with endovascular stenting. Lumbar cerebrospinal fluid drainage (n = 23) and somatosensory evoked potential monitoring (n = 15) were performed selectively in patients with significant aneurysm extent or with prior abdominal aortic aneurysm repair (n = 17). Spinal cord ischemia occurred in 5 patients (6.6%); two had lower extremity somatosensory evoked potential loss after stent deployment and 4 developed delayed-onset paraplegia. Two had full recovery in response to arterial pressure augmentation alone. Two had full recovery and one had near-complete recovery in response to arterial pressure augmentation and cerebrospinal fluid drainage. Spinal cord ischemia was associated with retroperitoneal bleed (n = 1), prior abdominal aortic aneurysm repair (n = 2), iliac artery injury (n = 1), and atheroembolism (n = 1). Conclusions Early detection and intervention to augment spinal cord perfusion pressure was effective for decreasing the magnitude of injury or preventing permanent paraplegia from spinal cord ischemia after endovascular stent repair of descending thoracic aortic aneurysm. Routine somatosensory evoked potential monitoring, serial neurologic assessment, arterial pressure augmentation, and cerebrospinal fluid drainage may benefit patients at risk for paraplegia.

Background The safety of cerebrospinal fluid (CSF) drainage in thoracic aortic surgery using extracorporeal circulation (ECC) with systemic heparinization has not been established. Methods Four hundred thirty-two patients had descending thoracic or thoracoabdominal aortic repair between 1993 and 2002. One hundred sixty-two of those patients (age range, 67 ± 13 years) had repairs performed with ECC, systemic anticoagulation, and lumbar CSF drainage. Repairs performed without CSF drainage, without ECC, or by stent graft (n = 53) were excluded. The CSF catheters were inserted at L3 to L5. Cerebrospinal fluid was drained to maintain pressures of 10 to 12 mm Hg. In the absence of neurologic deficit or coagulopathy, the catheters were capped at 24 hours and removed at 48 hours. Cerebrospinal fluid drainage was continued beyond 24 hours for delayed onset paraparesis. Results Cerebrospinal fluid drains were used in 135 thoracoabdominal aortic aneurysms (extent I, n=63; extent II, n=25; extent III, n=39; extent IV, n=8) and 27 descending thoracic aortic repairs (aneurysm, n=24; traumatic aortic injury, n=2; aortic coarctation, n=1). Partial left heart bypass was used in 132 patients, full cardiopulmonary bypass without deep hypothermic circulatory arrest in 5, and cardiopulmonary bypass with adjunctive deep hypothermic circulatory arrest in 25. Time between catheter insertion and anticoagulation was 153 ± 60 minutes. Heparin achieved an average maximum activated clotting time of 528 ± 192 seconds. Average ECC time was 114 ± 77 minutes. Average deep hypothermic circulatory arrest time was 40 ± 12 minutes. Mortality was 14.1% (23 of 162), and permanent paraplegia was 4.9% (8 of 162). No epidural or spinal hematoma was observed. Six (3.7%) patients had catheter-related complications (temporary abducens nerve palsy [n = 1]; retained catheter fragments [n = 2]; retained catheter fragment and meningitis [n = 1]; isolated meningitis [n = 1]; and spinal headache [n = 1]). Conclusions The CSF drainage in thoracic aortic surgery using ECC with full anticoagulation did not result in hemorrhagic complications. The permanent paraplegia rate in this complex patient population consisting of combined distal arch, thoracoabdominal aortic procedures were low, and lumbar CSF catheter-related complications had no permanent sequelae.

Background . Delayed postoperative paraplegia is a recognized complication of thoracic (TAA) or thoracoabdominal aortic aneurysm (TAAA) repair. The purpose of this study was to evaluate the effectiveness of interventions to treat delayed-onset paraplegia. Methods . Between January 1, 2000 and August 31, 2001, 99 patients underwent surgical repair of TAA, Crawford type I, II, or III TAAA. Standard intraoperative management included distal aortic perfusion and cerebrospinal fluid (CSF) drainage unless contraindicated. Therapeutic interventions to treat delayed paraplegia included lumbar CSF drainage and vasopressor therapy. Results . Three of the 99 patients had paraplegia upon awakening. Delayed-onset paraplegia occurred in 8 patients, 2 of whom had recurrent episodes. In those 8 patients, the initial episode occurred at a median of 21.6 hours (range 6.4 to 110.0 hours) after surgery and the second episode averaged 176 hours after surgery. At the onset of paraplegia, the average mean arterial pressure was 74 mm Hg and CSF pressure was 14 mm Hg. Three of the 8 patients had a functioning CSF catheter at the onset and the other 5 patients had catheters subsequently placed. Therapeutic interventions increased blood pressure to a mean arterial pressure of 95 mm Hg and decreased CSF pressure to 10 mm Hg. Five of the 8 patients with delayed-onset paraplegia made a full neurologic recovery and 3 had partial recovery. Conclusions . Patients with delayed-onset paraplegia had an increased chance of recovery as compared with those patients in whom paraplegia was diagnosed upon emergence from anesthesia. Acute interventions directed to increase spinal cord perfusion by increasing systemic blood pressure and decreasing CSF pressure were effective for the reversal of delayed onset of paraplegia after TAA or TAAA repair, resulting in an overall 3% incidence of permanent paraplegia and 3% incidence of residual paraparesis.

Deep hypothermia is an important cerebral protectant and is critical in procedures requiring circulatory arrest. The purpose of this study was to determine the factors that influence the neurophysiologic changes during cooling before circulatory arrest, in particular the occurrence of electrocerebral silence.In 109 patients undergoing hypothermic circulatory arrest with neurophysiologic monitoring, five electrophysiologic events were selected for detailed study.The mean nasopharyngeal temperature when periodic complexes appeared in the electroencephalogram after cooling was 29.6 degrees C +/- 3 degrees C, electroencephalogram burst-suppression appeared at 24.4 degrees C +/- 4 degrees C, and electrocerebral silence appeared at 17.8 degrees C +/- 4 degrees C. The N20-P22 complex of the somatosensory evoked response disappeared at 21.4 degrees C +/- 4 degrees C, and the somatosensory evoked response N13 wave disappeared at 17.3 degrees C +/- 4 degrees C. The temperatures of these various events were not significantly affected by any patient-specific or surgical variables, although the time to cool to electrocerebral silence was prolonged by high hemoglobin concentrations, low arterial partial pressure of carbon dioxide, and by slow cooling rates. Only 60% of patients demonstrated electrocerebral silence by either a nasopharyngeal temperature of 18 degrees C or a cooling time of 30 minutes.With the high degree of interpatient variability in these neurophysiologic measures, the only absolute predictors of electrocerebral silence were nasopharyngeal temperature below 12.5 degrees C and cooling longer than 50 minutes.

A 75-year-old woman described having shortness of breath. Four months earlier she had undergone coronary artery bypass grafting and undersized annuloplasty for treatment of ischemic mitral regurgitation (IMR). Real-time three-dimensional echocardiography revealed annuloplasty ring (AR) dehiscence (Fig 1A) from the posterior annulus (PA) and recurrent IMR (Fig 1B). Often the degree of annular undersizing necessary to restore valve competence in IMR is substantial and predisposes to ring dehiscence. Customized software was used to generate a quantitative three-dimensional model of the patient’s valve, including leaflets (anterior, AL; posterior, PL), annulus (An), annuloplasty ring (AR), and regurgitant orifice area (ROA) (Fig 1C, D). Such modeling techniques are rapidly evolving and in the future will allow annular and leaflet stress to be determined before and after operation. Inasmuch as most repair failures are stress related, these models should promote the development of patient-specific strategies that improve the results of mitral repair operation. Fig 1